20873 ÷ 2 = 10436 R1
Let's divide 20873 by 2.

Step 1:
2 goes into 2 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 2 from 2 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 2

Step 2:
2 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 10
Subtract 0 from 0 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 2

Step 3:
2 goes into 8 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 104
Subtract 8 from 8 to get 0.
Bring next digit (7) of the dividend behind the 0 and repeat the process: 7 / 2

Step 4:
2 goes into 7 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 1043
Subtract 6 from 7 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 2

Step 5:
2 goes into 13 6 times with a remainder of 1.
Write down 6 as next digit of of the result. 
Result so far: 10436
Subtract 12 from 13 to get 1.

The final result is 10436 with a remainder of 1.